Welcome to the Darrouzet-Nardi Lab homepage!
I am an assistant professor in the Biological Sciences department at the University of Texas at El Paso. I started at UTEP in January and am setting up my research program. The goal of my program is to examine the effects of global change drivers such as climate change on mountain, desert, and Arctic tundra ecosystems using ecological field experiments.
I will be recruiting students soon, so please let me know if you are interested in joining my lab!
Please check out my Science Blog, twitter feed, and CV to learn more about my research interests. There are short descriptions of some of the cool projects I've worked on below. My current research goal at UTEP is to get my lab up and running and to acquire funding to continue my research work in both dryland and Arctic tundra ecosystems.
Department of Biological Sciences
500 W. University Ave.
University of Texas at El Paso
El Paso, TX 79968
Climate change in dryland ecosystems
Just before I came to UTEP, I began working on a project designed to explore the response of biological soil crusts to elevated temperature and changing moisture regimes. Our analyses of carbon fluxes in a multiyear 2°C warming experiment (IR lamps) showed clear temperature effects on net soil exchange (NSE) of CO2 both throughout the year and between warming treatments and controls. These results provide experimental evidence for the hypothesis that increased temperature in semiarid ecosystems will drive carbon loss in crust-dominated soils.
Changing seasonality of plant-soil interactions in the Arctic tundra
Arctic soils contain large stocks of carbon and may act as a significant CO2 source in response to climate change. However, nitrogen availability limits both plant growth and decomposition in many Arctic sites and may thus be a key constraint on climate-carbon feedbacks. Using an early-snowmelt×warming manipulation at a site near Toolik Field Station on Alaska's North Slope, our team investigated changes in soil nutrient cycling in response to changing climate and seasonality. Our results indicate that snowmelt acceleration causes more rapid early-season nutrient immobilization in soils and that snowmelt acceleration in unwarmed plots can cause season-long reductions in root growth and inorganic N availability due to plant exposure to harsh conditions in the absence of snow.
Landscape heterogeneity of nitrogen cycling in an alpine-subalpine ecosystem (Dissertation)
Microbially mediated nitrogen cycling rates are heterogeneous across landscapes, with disproportionate activity occurring in biogeochemical hot spots. My dissertation examined landscape heterogeneity in soil nitrogen (N) cycling pools and fluxes in a 0.89 km2 site at the alpine-subalpine ecotone. Some of my key findings were: (1) A large percentage of total inorganic N pool sizes and associated cycling rates were attributable to a small percentage of hot spot locations across the landscape. (2) Although spatial variation in the timing of hot spots spreads the influence of short-term hot spots across the landscape, spatial variation in inorganic N availability was still important when integrated over one year. (3) A spatially complementary relationship was discovered between atmospheric N deposition and N-fixing plant abundance.
Sagebrush encroachment in subalpine meadows of the Sierra Nevada Mountains
Meadows in the southern Sierra Nevada Mountains have been encroached upon by sagebrush (Artemisia rothrockii) due to groundwater decline associated with livestock grazing. Our team conducted a three-year study on the ecosystem effects of this encroachment. We discovered that sagebrush transpiration does not dry out the soil during encroachment as we hypothesized it might. Using stable oxygen isotopes, we also showed that both young sagebrush plants and resident herbs used shallow soil water but were also able to access deeper water.